Wiring Transfer Switch

Ako Ako said:

If possible would someone explain in simple terms which of the connection's i need to connect which cables to in order to have everything functioning again .

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Hi - looking at the spec sheets, this device is a contactor. It has 4 double pole switches, 2 normally open and 2 normally closed. It’s rated at 10A. Perhaps it forms part of an Automatic Transfer Switch, as it can’t perform all the ATS functions by itself. So for me, I think its best to get ‘on site’ expert assistance to recommission your ATS.

Thank you Wilko but im confused now , it has been working as an automatic transfer switch for the last 10 years . Once a generator is started it automatically disconnects the power coming into it from the Inverter and connects the power coming into it from the generator . Once the generator is switched off the reverse happens and in the house continues to receive interrupted power , the change over is so fast its very rare tha anything will be effected , occasionally the Internet Router has to be rebooted or the TV goes into standby but thats a very rare occurrence . The Inverter is 1500 watts and the generator 1000 watts so the power consumption i the house is low .

I agree with @Wilko
it is not an automatic transfer switch, it is a contactor (big relay)

an ats will incorporate the following features.

guaranteed break before make switch over

some form of monitoring, to ensure the 2 supply’s can not be joined together even if a fault occurs and a contact becomes welded or physically stuck

an option to delay switching so as not to introduce a surge to the equipment being supplied

normaly there will also be the ability to lock the switching arrangement to supply 1, 2, or off so maintenance can be done without the risk of unexpected energising of a circuit.

what you have there is a poorly designed changeover system, although it seems to work or at least has at some point in the past, it is entirely possible under some conditions to do one of the following.
damage the generator by back feeding power from the inverter.
damage the inverter by back feeding from the generator
injure or kill someone working on either part of the system by energising something expected to be dead.

this is what I have to switch between grid supply and backup generator, it deals with safe switching, auto starting of generator, warm up and cool down delays etc.

Agree with James. It is just a 10A-rated contactor wired as 2-pole changeover which in theory will act as a transfer switch and I don't doubt that it has been working. But it is not the proper tool for the job due to the shock risk or damage that might occur if it malfunctions or the contacts flash over.

The unasked question here is Why?
Why, if it's been working for the last ten years, has it been cut out out the circuits?
And then, Who?
Who has done this?

Timbo , the answer to your question is the switch was in a building that also housed the generator but has now been demolished , the generator and switch were to be situated somewhere more convenient and much closer to the inverter and other equipment . Looking back i found out that the switch was installed closer to 15 years ago and i was the one to do it . I took the switch out of a friends house when he did away with all his solar equipment and recall having a simple wiring diagram with every connection number and the internal circuit shown shown so was a simple process of working out each connection . Now i feel rather stupid because i expected to go online again and find the same diagram when the time came , unfortunately i haven't been able to find it .
The switch was fitted by a self taught solar engineer to my friends house for the exact purpose i have been using it , i wouldn't be surprised if he has installed upwards of 100 between the early 2002 and 2018 as this part of Spain is very rural and without infrastructure cover outside the towns .
On the plus side i have taken note of everything explained in the advice posts and decided not to use the switch again but to return to the method i previously used before installing this switch which was a simple 3 position heavy duty 3 position manual switch . Center position was off , left connects one circuit , right another circuit , that way its not possible to connect one circuit without first disconnecting the other so only one circuit can be live at a time , the switch will be next to the generator so no hardship .
Reading the posts above i remembered a friend who came home one night and his inverter had shut down to protect his battery bank due to low voltage , without realizing it he made up and connected a cable with 2 male plugs and connected it between his generator into an outside socket , cost him 4,000 euros for a new Inverter .

I do have another query which someone might know the answer to . Until recently if we have bad weather for a couple of days and out battery bank power is low i would start the generator and it would disconnect the Inverter and power the house at the same time as charge the batteries at around 20 amps x 24 volts decreasing as the voltage in the batteries rise . A friend also with solar does it differently , when he starts his generator it only sends power to charge the batteries , the house continues to be powered by the inverter from the batteries so the charge is going into the batteries at the same time as being drawn from them as it would be during the normal charging process in the daytime from the solar panels so the charge stays about the same as the voltage in the batteries doesn't rise by a lot . We have always disagreed on which is the most efficient method so an opinion would be very much appreciated . My thoughts are that the time the generator is running is saving power being drawn from the batteries although what's going into them reduces as they charge , his opinion is that he gets more going into his batteries because the charging amps dont reduce while he is still having power for the hours the generator is running .

Ako Ako said:

he made up and connected a cable with 2 male plugs

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Could have been worse - those things are known as "widowmakers".

We have always disagreed on which is the most efficient method so an opinion would be very much appreciated

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Your method is probably better. When the generator is running, powering the house load directly from it allows the entire charger output to be delivered to the battery. As you say, there is a point in the charging process at which the battery can no longer utilise the full output capability of the charger, but up to that point any demand made by the inverter is unavailable for charging, so the charge time is increased. The charging profile can also be affected when the inverter is absorbing a significant fraction of the charger output, as the charger cannot sense the battery condition as accurately.

At best, if the charger were amply big enough to supply both the demand of the inverter and as much as the battery can accept, and able to correctly monitor the battery despite the inverter load, the main disadvantage would be about 25% increase in generator fuel consumption due to the losses incurred by converting the 230V AC to battery voltage DC, and then back to 230V AC. This is normal in a high-performance on-line UPS where the load is always supplied from the inverter, but not usually justified elsewhere.

If you can tolerate the momentary break in the supply, transfer the house load to the generator for faster charging and marginal fuel saving.